radeon: add RS400 family support.

This adds support for the RS400 family of IGPs for Intel CPUs.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_drv.h b/drivers/gpu/drm/radeon/radeon_drv.h
index 9d752bc..9278429 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.h
+++ b/drivers/gpu/drm/radeon/radeon_drv.h
@@ -123,6 +123,7 @@
 	CHIP_RV380,
 	CHIP_R420,
 	CHIP_RV410,
+	CHIP_RS400,
 	CHIP_RS480,
 	CHIP_RS690,
 	CHIP_RS740,